BUGS:
-Backingstore feature does not work...why???

TODO:
-rewrite Makefile
-fix header for gcc-3.x
-English Manual
-simplify Menu routine (avoid heavy load)

-show title text
-string type (length of float) of number for axis
-support rotated text
-make margin variable
-how to utilize XSizeHints?
-enable 'try' and 'catch'

-PShandling
--make class for PS handling
--PS for pset, line type?
--optimize PS output
--support PS output for dotted line  [2 2] 0 setdash 
